[PATCH] D15240: X86: Don't emit SAHF/LAHF for 64-bit targets unless explicitly supported

[Michael Hordijk via llvm-commits]

hoffbrinkle added a comment.

In http://reviews.llvm.org/D15240#332004, @jfb wrote:

>




> Agreed, you'll need to compile with `-mattr=+sahf` to avoid that issue.


Well, right, but when not using that attribute, we shouldn't generate incorrect code.  llvm shouldn't issue a POPFQ unless it knows that it's not blowing away an updated EFLAGS.


Repository:
  rL LLVM

http://reviews.llvm.org/D15240